The invention relates to a sewing machine having a transport device for the material to be sewn, which transport device includes a transporter which engages on one side of the material to be sewn and a presser foot which can be placed on the other side of the material to be sewn in the effective area of the transporter.
Although in the known sewing machines of this type the transporter performs a straight transport movement, not only straight seams but also so-called inside curves, i.e., seams that curve in a concave manner when viewed from the edge of the material to be sewn, can be performed at high speed with the use of an edge guide. In contrast, to sew an outside curve, i.e. a seam along a path curved in a convex manner as viewed from the edge of the material to be sewn, the operator must manually guide the material to be sewn, which, independent of the ability of the operator, requires to a greater or lesser degree, a reduction in the sewing speed in order to be able to produce the seam with the necessary precision. Above all, with sewing material in which the outside curve comprises a substantial proportion of the overall sewing length, such as is the case, for example, with pocket pouches for pockets in clothing items, the reduction in operating speed during sewing of the outside curve does not permit full usage of the capacity of the sewing machine.